gistfile1.m

// AGSyncPipe protocol
@protocol AGSyncPipe 
// to dicuss: conflict callback could also have baseObject for 3 ways merge options
-(void) save:(AGSyncObject*) object
     success:(void (^)(id responseObject))success
     failure:(void (^)(NSError *error))failure
    conflict:(void (^)(NSError *error, AGSyncObject* fromObject, AGSyncObject* toObject))conflict;

-(void) read:(void (^)(id responseObject))success
     failure:(void (^)(NSError *error))failure;
     
-(void) read:(id)value
     success:(void (^)(id responseObject))success
     failure:(void (^)(NSError *error))failure;
     
-(void) remove:(NSDictionary*) object
       success:(void (^)(id responseObject))success
       failure:(void (^)(NSError *error))failure;
@end

//Our SyncObject with its sync needed metadata 
@interface AGSyncObject : NSObject
@property (nonatomic, readonly) NSString* objectId;
@property (nonatomic, readonly) NSString* revision;
@property (nonatomic, strong) id content;
@end